Cancer care and palliative care each require a complex multi- and interdisciplinary approach to maximize the care of people with cancer. Recommendations for cancer treatment should both relieve the symptoms of cancer and prevent and treat side effects of anticancer therapy. Unrelieved symptoms not only contribute to worse quality of life but also can reduce a patient's ability to tolerate cancer therapy and may have a negative impact on survival. Consistent integration of palliative care practices into standard oncology care is needed across the trajectory of the cancer experience. This article will review the overlap between palliative care and oncology and discuss the available evidence that true integration of palliative and oncology care provides patients with optimal oncology care.